The invention relates to an elecerochromic glass component, particularly for motor vehicle mirrors, which contains a doped ion-conducting basic polymer as the ion-conducting layer.
Electrochromic mirrors, particularly for motor vehicles, are known in the state of the art. The essential element of these electrochromic mirrors is a layer of electrochromic material. A material is termed electrochromic when it changes its optical constants (n, k) and hence its optical properties on application of an electric field. Typical examples of such electrochromic materials are WO3 and MoO3, which are virtually colourless when applied to a substrate in thin layers. An electrochromic layer may change its optical properties by oxidation or reduction processes. If protons move in such a layer, in the case of tungsten oxide there is a reduction to blue tungsten bronze. The intensity of colouration is determined by the quantity of charge which has flowed in the layer.
Numerous electrochromic mirrors, particularly for motor vehicles, are now know from the state of the art and have electrochromic layers of this type in different layered structures. German 3 008 768 describes an electrochromic mirror which essentially consists of a layer system built on a glass substrate at least one electrochromic layer, at least two electrodes, at least one proton-conducting layer and at least one proton-delivering and one proton-storing layerbeing present.
The optical change properties of a mirror of this type are determined, inter alia, by the proton conductivity of the proton-conducting layer. The higher the proton conductivity, the higher also the rate of change of reflection. In the mirrors of the state of the art, proton-conducting glass plates, which were soaked with sulphuric acid, have been used hitherto as proton-conducting layers (for example in German Offenlegungaschrift 2 504 905) or as in German 3 008 768 so-called solid ion-conducting layers.
It has been shown all these ion-conducting layers from the state of the art used hitherto for the electrochromic glass components still do not have satisfactory results with regard to ion conductivity. Furthermore, it is disadvantageous for the mirrors of the state of the art, that the ion-conducting layers described there are either too thick or are too complex and expensive as regards their mode of manufacture.
The object of the present invention is therefore, starting from the electrochromic mirror as described in german 3 008 766, to indicate a significantly improved embodiment which is characterised particularly by an ion-conducting layer which is favourable to apply as regard to manufacture and processing and furthermore has a high ion conductivity, with which it is possible to change the electrochromic layer quickly.
The invention is achieved by the characterizing features of patent claim 1. The sub-claims show advantageous further developments.
According to the invention it is thus proposed to use a doped ion-conducting basic polymer as the ion-conducting layer. It has been shown that these doped ion-conduction basic polymers are particularly well suited. The doped ion-conducting basic polymer is preferably selected from polybenzimidazoles (PBI), polypyridines, polyimidazoles, polybenzthiazolea, polybenzoxazoles, polyquinolines, polythiazoles, polyoxadiazoles and polytetrapyrenes. The ion-conducting layer is thus a layer which preferably conducts protons. However, in principle the layer is also suitable for other ions, such as for example lithium.